campbell



, (No Model.) l 2 Sheets-Sheet 1.

,J. CAMPBELL.

ROASTING 0R RENOVATING FURNACE.

No. 255.592. Patented MaJr. 28.1882.

\XHTNEQEES: Elm/EN ER:

(No Model.)

J. CAMPBELL.

BOA-STING 0R RENOVATING FURNACE.

N0 255,592. Patented Mar.28,188'2.

INVENTIjR 2'sneets-sheet 2.

UNITED STATES PATENT OF ICE.

JOHN CAMPBELL, OF ALLEGHENY CITY, PENNSYLVANIA, ASSIGNOR TO THE CAMPBELL DESULPHURIZING COMPANY, OF NEW YORK, N. Y.

ROASTING OR RENOVATING FURNACE.

SPECIFICATION formingpart of Lettersl atent No. 255,592, dated March 28, 1882,

i Application filed May 5, 1881. (No model.)

To all whom tt may concern:

Be it known that I, JOHN CAMPBELL, of Alleghen y City, Allegheny county, Pennsylvania, have invented certain new and useful Improvements in Roasting or Renovating Furnaces, of which the followingis a specification.

My invention applies to furnaces for roasting or desulphurizing ores, or for renovating bone-black or similar materials, in which the [O granulated material to be purified is showered, down a vertical shaft through which flame rises to burn out or dissipate the consumable or volatile impurities therefrom.

My present invention is partly an improvementonafurnace of similar character on which an application was filed August 11, 1880; and it consists partly in a peculiar form of shaft which secures an agitated zigzag passage of the falling ore, and a similar zigzag reverberating passage of the ascending flame; and it also partly consists in means for producing a forced draft through the shaft, and of 'collecting and saving the utilizable or valuable products of combustion or other matters arising from the material acted upon, as hereinafter fully set forth.

Figure l of the annexed drawings presents avertical sectional elevation of a furnace of thedescribed kind, showing the lower part or furnace proper, with the receptacle for the pnrified material, and a portion of the shaft rising between the two, in the construction of which shaft my invention is partly embodied. Fig. 2 is a vertical sectional elevation of the complete furnace or plant constructed according to my invention, showing the furnace, shaft, and flues, with means for producing forced draft and receptacles for receiving the purified material falling from the shaft, and for collecto ing and recovering the volatile or utilizable matters from the draft of the shaft.

'In Fig. 3 I have shown the complete apparatus as erected with a shaft of the kind shown in my previous application before referred to, and in, Fig. 1 I show an enlarged view of the form of shaft which I prefer to use in this case; but either kind may be used in connection with the other features of my invention, as each kind of shaft acts 011 a simi o lar principle while differing in structure.

The shaft B in Fig. 3 is composed of aseries of internal and external cones arranged coucentrically, so as to form an annular conicall y contracting and diverging passage, down through which the granulated material is show- 5 5 cred from the top, while flame ascends through the same from the bottom. The several internal and external cones of the shaft, as will be observed, arrest and deflect the falling material at frequent intervals, and compel it to take a rattling zigzag passage alternately converging and diverging, while thefiame takes a zig-- zag reverberating passage in reverse order, so that a most energetic agitation of-the falling material and the most eifective contact of the fiametherewith are produced, which results in the almost perfect consumption or dissipation of the impurities from the ore or other material treated, as will be appreciated. The shaft, as shown in the drawings, rises from a strong 7o foundation, (6, to a suitable height-say from. fifty to one hundred feet, more or less, accord-f ingto circumstances.

The conical shaft shown in Fig. 3 is supposed to be formed of cast-iron, the outer portion being supported on the top of the foundation and formed of a series of truncated cones superposed and secured together at their meeting flanges, as indicated. The inner cones are formed in similar sections, which are fixed on a central rod or tube which han gs from a strong cross-bar at the top, and is stepped and sup-' ported on the foundation, as illustrated. A shaftof this construction is not readily made in fire-clay or similar fire-proof material, but: 8 is more conveniently made of cast-iron, which, however, is not so well suited for some purposes, where the very high heat necessary topurify some substances injuriously affects the structure, whereas for other purposes, where 0 such intense heatis not required, an iron structure is preferable. For this reason I have dc signed the special form of shaft A shown in Fig.1, which may be constructed entirely of fire-brick or similar refractory material, and 5 is capable of withstanding any degree of heat necessary in treating any ofthe usual materials. This shaft rises directly from the foundation, and is preferably made wholly of fire-brick, or fire-brick on the inner courses and common roo brick on the outer courses, as will be understood. The fine or passage of the shaft may be either round or square, or of other form in cross-section, as will be understood, the square form being represented in the drawings.

In lieu of the arrangement of cones as in my previous shaft, I employ a series of bars, 7', extending across the shalt, one above the other at frequent intervals, as illustrated. These bars are of angular or prismatic form in cross-section, arranged with their angles or cones uppermost and their sides inclining to the sides of the shaft, and they are placed successively at right angles or diagonal to each other, or in regular spiral relation, orin other angular positions, as will be understood from Figs. 1 and 2, so that a central vertical section of the shaft, as in Fig. 1, presents in efiect a superposed series of cones or pyramids similar to that of Fig. 3, which insures an agitated zigzag rattling passage of the falling ore, &c., and a reverberated passage of the ascending flame, in a manner substantially the same as already described in connection with the conical shaft in Fig. 3. It will be observed, however, that the cross-bars r of Figs. 1 and 2 may be made of fire-clay, either solid or in the form of tubes, as shown in Fig. 1, in the manner of retorts, and may be firmly supported at either end in the brick-work of the shaft, thus forming a durable, substantial structure capable of resisting the intense heats usual in any metallurgical operation. 7

Considering now that either form of shaft maybe used as occasion demands, I will describe the remainder of the apparatus.

. At the base of the shaftis an inclined chute or hopper, c, which receives the purified material as it arrives at the bottom of the shaft and discharges it into an accumulating-receptacle, d, adjoining one side of the shaft.

6 is a curved pipe or flue, which opens upwardly in-the base of the shaft and conveys the heat and flame thereto from an ordinary coal-furnace, as in Fig. 1, or from a special form of gas-burner, as in Fig. 3.

The furnacef in Fig. 1 may be fed with coal or other solid fuel, and by means of a forced blast an energetic combustion is produced, so as to deliver a great volume of flame orhotgasesfrom thefluee,which,risingthrough the shaft, as before described, purities the ma terial which may be showered through the same.

In Fig. 3 a special form of gas-burner now used connects with the outer end of the flameflue. In this caseg indicates amain steampipe, from which a branch opens in the form of ajet into a tuyere or injector, h, directed into the flame-flue. The outer end of the tuyere is open to admit the inflow of air induced by the steam-jet, as illustrated, and to the tuyere also connects a hydrocarbon gas or oil pipe, 'i,which allows a regulated inflow of combustible gas or. oil,together with the air, as will be understood. Hence, when the burner is in operation, the steam, air, and hydrocarbon mingle, pass through the flue e, and rise in the shaft in voluminous tongues of flame. Air may be admitted at the base of the shaft through suitable openings, as seen in Fig. 1, if required to render the combustion in the shalt more perfeet.

The top of the shaft is surmounted by a hopper or receptacle, is, into which the pulverized ore, bone-black, or other material is fed, the materialbeing conveyed thereto by suitable elevators or other means, as will be understood. The neck of the hopper opens into the top of the shaft, and the material is fed from the same by a shaking or sifting device, Z, operated by asuitable motor from the base of the apparatus, so as to feed the material regularly in a distributed shower down through the shaft.

At the discharging end of the chute c in the receptacle is arranged an air-blast nozzle, m, which delivers a strong jet of cold air against the entering stream of purified ore or other material, which is presumed to issue from the chute in a red-hot condition, so that this air-jet serves to burn out the remnant of impurities that may have escaped dissipation in the shaft, and at the same time cools down the heated material preparatory to its removal. The purified material is removed from the receptacle throughthe door a, and the hot air escapes therefrom through the flue 0. The draft of the shaft is conveyed through a large descending flue, 8, opening from the top of the shaft and dipping at its lower end into a waterboxor condensing-chamber,p, so thatits mouth opens slightly below the level of the fluid therein, or just on a level therewith, as illustrated. this level being kept constant by a supply of water and a regulating float-valve, as will be understood.

From the main steam pipe g a branch extends into the descending flue and terminates in an outwardly-directed jet or nozzle, t, from which a strong steam-jet is emitted, which produces by induction a powerful current in the flue, which withdraws the draft from the shaft and forces the air, gases, and dust or ashes through the water or other liquid in the chamber. It will hence be seen that valuable metallic dust or other solid matter suspended in the draft will be arrested by the water and deposited therein, thus enabling the same to be recovered when required, while the soluble or condensible vapors or gases will be absorbed or dissolved by the water or other fluid, which may, after it is sufficiently charged, be drawn off and thus utilized. In treating sulphurous ores this water will possess a sulphurous or sulphuric character, and may be utilized as sulphurous or sulphuric acid after appropriate treatment, while gold or other metallic dust may be-recovered from the precipitate in the vessel. Hence not only are valuable products thus obtained from the draft of the shaft which would otherwise be wasted, but irritating or poisonous matters are arrested and prevented from polluting the surrounding air.

From the top of the chamber 1) a high vertical flue rises and opens at the top into the atmosphere, and thus serves to carry off the fixed or useless gases after their passage through the water in the condensing-chamber, and at the same time assists the draft or action of the jet t, as will be understood. t

It will therefore be seen that by these combined improvements I-produceavery complete apparatus for the described purposes, which not only embodies a substantial and durable fire-proof structure of the shaft and means for energetically agitating the falling ore and subjecting it to the action of flame in the most efficient manner, butalso includes means for producing a powerful forced draft through the shaft, and. for arresting and recovering the utilizablematters therefrom, which renders my apparatus an important improvement in this line.

1 do not here claim the conical form of shaft shown in Fig. 2, as the same is claimed in my former application beforereferred to. Neither do I broadly claim a water-box or condensingchamber in connection with descending and ascending flues. I

I am also aware that ore-shafts have been formed with angular bars extending across the same; but in such cases the bars have been arranged in parallel order, one above the other, and in several vertical lines or rows side by side, whereas I employ but one vertical line or series of overlying bars, which are placed at various angles to each other or in spiral order, whereby I secure a better result with a much simpler construction.

What I claim is- 1. A roasting-furnace having a shaft formed with a series of bars extending across its passage, with their. sides inclined to the axis of the shaft and arranged one above the other at various angles in spiral order, substantially as and for the purpose set forth 2. In a roasting -furnace, a shaft provided with a series of hollow bars permanently built into it, said hollow bars having inclined upper and lower surfaces and arranged one above the other in spiral order, substantially as and for the purpose specified.

3. The combination, with the shaft A, provided with air-passages o, the furnace f, and the receptacle (1, located at opposite sides of said shaft, of the chute 0, having its upper end of substantially the same size as the interior of the shaft, and the blast-pipe 6, extending into the shaft through the center of the chute O, the lower ends of the pipe 6 and chute (lextending through opposite walls of the shaft and entering respectively the furnace f and the receptacle d, substantially as shown and described.

' JOHN CAMPBELL.

' IVitnesses: v

CHAS. M. HIGGINS, WM. S. BOOTH. 

